1. Area of the Invention
The invention relates to the field of aroma substances and further relates to substance mixtures of starch derivatives and bitter principles, foods containing these substance mixtures, methods of their production, and use of the starch derivatives to mask undesired flavour profiles.
2. State of the Art
Good medicine is bitter to the mouth—this simple formula does not only confirm our life experience, but it is a fact that many natural active agents do have a positive effect on the human organism but they taste bitter and astringent. The group of polyphenols is a typical example thereof, specifically the proanthocyanidins and catechins, which are found in plants as different as litchis and green tea, but also in red clover. These groups of substances have been known for a long time for their blood-purifying and antihypertensive effects, and also the liquid-liquid extraction of the active agents does not present a particular preparative difficulty. Still, it has been hardly possible to add these substances to foods as additives, as their unpleasant taste cannot be masked, even by adding intense sweeteners.
The subject matter of International patent application WO 2006 085710 A1 (Amorepacific) discloses a process for the production of granulated green tea powder, to which small amounts of the most diverse substances are added as binders, among which are also catechins and maltodextrins. The publication does not mention an improvement in flavour.
International patent application WO 2008 059609 A1 (Kao) discloses a reduction of bitterness and astringency of non-polymerized catechins in beverages by adding sweeteners such as thaumatin, glycyrrhizine, sorbitol or erythritol.
From the International patent application WO 2011 141350 A1 (Unilever) it is known that the addition of water-soluble gum arabic or pectins reduces the bitterness and the astringency of catechins in beverages.
European patent application EP 1959754 A1 (Coca Cola) proposes a ternary mixture of sweeteners comprising inter alia carbohydrates and hydration products. Among many other suitable carbohydrates also maltodextrins are mentioned, and flavanols and flavanals are suitable hydration products, among others. However, combinations of both substance groups are not disclosed.
Furthermore, U.S. Pat. No. 8,003,150 (Kraft) discloses the production and use of flavonoids, which are added up with glucose, galactose or other reducing sugars. By adding sugars to the flavonoids, bitterness and astringency are reduced.
The subject matter of the Japanese patent application JP 2008 118873 A1 (Taiyo) is the improvement in flavour of beverages containing green tea extract by adding highly branched cyclic dextrins.
In addition, the Japanese patent application JP 08 298930 A1 describes a method in which a dextrin, a cyclodextrin and/or starch as well as the enzyme cyclo maltodextrin glucanotrans-ferase is added to a tea extract or a tea beverage. After the enzyme has taken effect a reduction of bitterness and astringency is perceptible.
Finally, solid tea preparations are known from Chinese patent application CN 101103753 A1 (Anhui Fuyang), containing also catechins and maltodextrin besides polyvinyl pyrrolidone and magnesium stearate. The preparations are characterized in that they are effective against high blood pressure. Any improvement in flavour is not reported.
Therefore, the object of the present invention was to provide substance mixtures comprising bitter principles, specifically polyphenols, and, particularly, catechins together with a food-grade masking agent such that the mixtures will have a neutral taste. It was a further object to provide sufficiently water-soluble substance mixtures allowing a simple incorporation into liquid compositions such as, for example, beverages and particularly instant tea beverages.